System Architecture¶

Overview¶

The Gustaffo Reservations Application follows a microservices architecture pattern to provide a scalable, maintainable, and resilient system for hotel reservation management. The architecture is designed to handle high traffic volumes and integrate with multiple external systems.

Architecture Diagram¶

flowchart TB
    subgraph "Frontend"
        UI[Web UI]
        Mobile[Mobile App]
    end

    subgraph "API Gateway"
        Gateway[API Gateway/Load Balancer]
    end

    subgraph "Core Services"
        Reservation[Reservation Service]
        Payment[Payment Service]
        Offer[Offer Service]
        Notification[Notification Service]
        User[User Service]
    end

    subgraph "Integration Layer"
        PMS[PMS Integration]
        Payment_Gateway[Payment Gateway Integration]
        OTA[OTA Integration]
    end

    subgraph "Data Layer"
        DB[(Primary Database)]
        Cache[(Cache)]
        Queue[(Message Queue)]
    end

    UI --> Gateway
    Mobile --> Gateway

    Gateway --> Reservation
    Gateway --> Payment
    Gateway --> Offer
    Gateway --> Notification
    Gateway --> User

    Reservation --> DB
    Payment --> DB
    Offer --> DB
    Notification --> DB
    User --> DB

    Reservation --> Cache
    Payment --> Cache
    Offer --> Cache

    Reservation --> Queue
    Payment --> Queue
    Notification --> Queue

    Reservation --> PMS
    Payment --> Payment_Gateway
    Offer --> OTA

    PMS --> External_PMS[Apaleo PMS]
    Payment_Gateway --> External_Payment[Payment Providers]
    OTA --> External_OTA[OTA Channels]

Key Components¶

API Gateway¶

Serves as the entry point for all client applications, providing:

Request routing
Load balancing
Authentication and authorization
Rate limiting
Request/response transformation

Core Services¶

Reservation Service¶

Manages the entire lifecycle of reservations, including:

Reservation creation and modification
Reservation status management
Availability checking
Room inventory management

Payment Service¶

Handles all payment-related operations:

Payment processing
Payment status tracking
Refund processing
Integration with payment gateways

Offer Service¶

Manages hotel offers and pricing:

Rate plan management
Special offer creation
Pricing rules and calculations
Discount management

Notification Service¶

Manages all communications with guests and hotels:

Email notifications
SMS notifications
Push notifications
Notification templates and localization

User Service¶

Manages user accounts and authentication:

User registration and profile management
Authentication and authorization
Role and permission management

Integration Layer¶

PMS Integration¶

Integrates with property management systems:

Apaleo PMS integration
Reservation synchronization
Room inventory synchronization
Payment posting

Payment Gateway Integration¶

Integrates with payment providers:

Credit card processing
Alternative payment methods
Payment authorization and capture
Refund processing

OTA Integration¶

Integrates with online travel agencies:

Channel management
Inventory and rate distribution
Booking retrieval

Data Layer¶

Primary Database¶

PostgreSQL database for persistent storage of application data.

Cache¶

Redis cache for high-performance data access and session management.

Message Queue¶

RabbitMQ for asynchronous communication between services and event-driven architecture.

Communication Patterns¶

Synchronous Communication¶

REST APIs for direct service-to-service communication
GraphQL for complex data queries

Asynchronous Communication¶

Message-based communication for event processing
Publish-subscribe pattern for event notifications
Event sourcing for maintaining system state

Deployment Architecture¶

The system is deployed on Kubernetes, providing:

Container orchestration
Automatic scaling
Service discovery
Health monitoring
Rolling updates

Security Architecture¶

Security is implemented at multiple levels:

API Gateway authentication and authorization
Service-to-service authentication
Data encryption in transit and at rest
Secure storage of sensitive information
Regular security audits and vulnerability scanning

Resilience and Fault Tolerance¶

The system is designed to be resilient:

Service isolation prevents cascading failures
Circuit breakers prevent overloading failing services
Retry mechanisms handle transient failures
Fallback mechanisms provide degraded functionality when services are unavailable
Redundancy eliminates single points of failure